diff --git a/CMakeLists.txt b/CMakeLists.txt
index ab90ef7cad3..9f9b3977106 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,6 +8,7 @@ set(INSTALL_LIB_DIR lib CACHE PATH "Installaction directory for libraries")
 set(INSTALL_INCLUDE_DIR include CACHE PATH "installaction directory for header files")
 set(INSTALL_CMAKE_DIR lib/cmake CACHE PATH "Installation directory for cmake files")
 
+option(S2N_NO_PQ "Disables all Post Quantum Crypto code. You likely want this for older compilers or uncommon platforms.")
 option(S2N_NO_PQ_ASM "Turns off the ASM for PQ Crypto even if it's available for the toolchain. You likely want this on older compilers." OFF)
 
 ##header files
@@ -23,13 +24,6 @@ file(GLOB ERROR_HEADERS
     "error/*.h"
 )
 
-file(GLOB PQ_HEADERS
-    "pq-crypto/*.h"
-    "pq-crypto/bike_r1/*.h"
-    "pq-crypto/bike_r2/*.h"
-    "pq-crypto/sike_r1/*.h"
-)
-
 file(GLOB STUFFER_HEADERS
     "stuffer/*.h"
 )
@@ -51,18 +45,32 @@ file(GLOB ERROR_SRC
     "error/*.c"
 )
 
-# The SIKE code #includes .c files directly, including all sike_r*/*.c breaks the build due to duplicates
-file(GLOB PQ_SRC
-        "pq-crypto/*.c"
-        "pq-crypto/bike_r1/*.c"
-        "pq-crypto/bike_r2/*.c"
-        "pq-crypto/sike_r1/fp_generic_r1.c"
-        "pq-crypto/sike_r1/P503_r1.c"
-        "pq-crypto/sike_r1/sike_r1_kem.c"
-        "pq-crypto/sike_r1/fips202_r1.c"
-        "pq-crypto/sike_r2/fips202.c"
-        "pq-crypto/sike_r2/P434.c"
-        )
+if(S2N_NO_PQ)
+    message(STATUS "S2N_NO_PQ flag was detected - Disabling Post Quantum Crypto")
+    # If all Post Quantum Code is disabled, also disable PQ assembly optimized code
+    set(S2N_NO_PQ_ASM ON)
+else()
+    file(GLOB PQ_HEADERS
+        "pq-crypto/*.h"
+        "pq-crypto/bike_r1/*.h"
+        "pq-crypto/bike_r2/*.h"
+        "pq-crypto/sike_r1/*.h"
+        "pq-crypto/sike_r2/*.h"
+    )
+
+    # The SIKE code #includes .c files directly, including all sike_r*/*.c breaks the build due to duplicates
+    file(GLOB PQ_SRC
+            "pq-crypto/*.c"
+            "pq-crypto/bike_r1/*.c"
+            "pq-crypto/bike_r2/*.c"
+            "pq-crypto/sike_r1/fp_generic_r1.c"
+            "pq-crypto/sike_r1/P503_r1.c"
+            "pq-crypto/sike_r1/sike_r1_kem.c"
+            "pq-crypto/sike_r1/fips202_r1.c"
+            "pq-crypto/sike_r2/fips202.c"
+            "pq-crypto/sike_r2/P434.c"
+    )
+endif()
 
 file(GLOB STUFFER_SRC
     "stuffer/*.c"
@@ -160,6 +168,10 @@ if(S2N_NO_PQ_ASM)
     target_compile_options(${PROJECT_NAME} PUBLIC -DS2N_NO_PQ_ASM)
 endif()
 
+if(S2N_NO_PQ)
+    target_compile_options(${PROJECT_NAME} PUBLIC -DS2N_NO_PQ)
+endif()
+
 target_compile_options(${PROJECT_NAME} PUBLIC -fPIC)
 
 target_compile_definitions(${PROJECT_NAME} PRIVATE -D_POSIX_C_SOURCE=200809L)
diff --git a/tests/unit/s2n_bike_r1_kat_test.c b/tests/unit/s2n_bike_r1_kat_test.c
index 9ce2d975e6d..7aaed20f508 100644
--- a/tests/unit/s2n_bike_r1_kat_test.c
+++ b/tests/unit/s2n_bike_r1_kat_test.c
@@ -26,11 +26,17 @@
 
 int main(int argc, char **argv, char **envp) {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
     }
 
     EXPECT_SUCCESS(s2n_test_kem_with_kat(&s2n_bike1_l1_r1, RSP_FILE));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_bike_r1_kem_test.c b/tests/unit/s2n_bike_r1_kem_test.c
index bc5a4aea7a8..ff9688c2b28 100644
--- a/tests/unit/s2n_bike_r1_kem_test.c
+++ b/tests/unit/s2n_bike_r1_kem_test.c
@@ -19,13 +19,16 @@
 
 int main(int argc, char **argv)
 {
+    BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     unsigned char publicKey[BIKE1_L1_R1_PUBLIC_KEY_BYTES];
     unsigned char privateKey[BIKE1_L1_R1_SECRET_KEY_BYTES];
     unsigned char clientSharedSecretPlaintext[BIKE1_L1_R1_SHARED_SECRET_BYTES];
     unsigned char serverSharedSecretPlaintext[BIKE1_L1_R1_SHARED_SECRET_BYTES];
     unsigned char encryptedSecret[BIKE1_L1_R1_CIPHERTEXT_BYTES];
 
-    BEGIN_TEST();
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
@@ -36,6 +39,8 @@ int main(int argc, char **argv)
     EXPECT_SUCCESS(BIKE1_L1_R1_crypto_kem_dec(serverSharedSecretPlaintext, encryptedSecret, privateKey));
     EXPECT_BYTEARRAY_EQUAL(serverSharedSecretPlaintext, clientSharedSecretPlaintext, BIKE1_L1_R1_SHARED_SECRET_BYTES);
 
+#endif
+
     END_TEST();
 }
 
diff --git a/tests/unit/s2n_bike_r2_kat_test.c b/tests/unit/s2n_bike_r2_kat_test.c
index bce0dade77b..a97249a49a4 100644
--- a/tests/unit/s2n_bike_r2_kat_test.c
+++ b/tests/unit/s2n_bike_r2_kat_test.c
@@ -26,11 +26,17 @@
 
 int main(int argc, char **argv, char **envp) {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
     }
 
     EXPECT_SUCCESS(s2n_test_kem_with_kat(&s2n_bike1_l1_r2, RSP_FILE));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_bike_r2_kem_test.c b/tests/unit/s2n_bike_r2_kem_test.c
index 844fa8ca3e7..5a640d5fd0f 100644
--- a/tests/unit/s2n_bike_r2_kem_test.c
+++ b/tests/unit/s2n_bike_r2_kem_test.c
@@ -19,13 +19,16 @@
 
 int main(int argc, char **argv)
 {
+    BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     unsigned char publicKey[BIKE1_L1_R2_PUBLIC_KEY_BYTES];
     unsigned char privateKey[BIKE1_L1_R2_SECRET_KEY_BYTES];
     unsigned char clientSharedSecretPlaintext[BIKE1_L1_R2_SHARED_SECRET_BYTES];
     unsigned char serverSharedSecretPlaintext[BIKE1_L1_R2_SHARED_SECRET_BYTES];
     unsigned char encryptedSecret[BIKE1_L1_R2_CIPHERTEXT_BYTES];
 
-    BEGIN_TEST();
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
@@ -36,6 +39,7 @@ int main(int argc, char **argv)
     EXPECT_SUCCESS(BIKE1_L1_R2_crypto_kem_dec(serverSharedSecretPlaintext, encryptedSecret, privateKey));
     EXPECT_BYTEARRAY_EQUAL(serverSharedSecretPlaintext, clientSharedSecretPlaintext, BIKE1_L1_R2_SHARED_SECRET_BYTES);
 
+#endif
     END_TEST();
 }
 
diff --git a/tests/unit/s2n_cipher_preference_test.c b/tests/unit/s2n_cipher_preference_test.c
index 6b9eea54958..080fac5abeb 100644
--- a/tests/unit/s2n_cipher_preference_test.c
+++ b/tests/unit/s2n_cipher_preference_test.c
@@ -43,8 +43,12 @@ int main(int argc, char **argv)
         EXPECT_TRUE(s2n_ecc_extension_required(preferences));
         EXPECT_TRUE(s2n_pq_kem_extension_required(preferences));
         EXPECT_EQUAL(4, preferences->kem_count);
+#if !defined(S2N_NO_PQ)
         EXPECT_NOT_NULL(preferences->kems);
         EXPECT_EQUAL(preferences->kems, pq_kems_r2r1);
+#else
+        EXPECT_NULL(preferences->kems);
+#endif
 
         preferences = NULL;
         EXPECT_SUCCESS(s2n_find_cipher_pref_from_version("KMS-TLS-1-0-2018-10", &preferences));
@@ -53,6 +57,7 @@ int main(int argc, char **argv)
         EXPECT_EQUAL(0, preferences->kem_count);
         EXPECT_NULL(preferences->kems);
 
+#if !defined(S2N_NO_PQ)
         preferences = NULL;
         EXPECT_SUCCESS(s2n_find_cipher_pref_from_version("KMS-PQ-TLS-1-0-2019-06", &preferences));
         EXPECT_TRUE(s2n_ecc_extension_required(preferences));
@@ -84,6 +89,20 @@ int main(int argc, char **argv)
         EXPECT_EQUAL(4, preferences->kem_count);
         EXPECT_NOT_NULL(preferences->kems);
         EXPECT_EQUAL(preferences->kems, pq_kems_r2r1);
+#else
+        preferences = NULL;
+        EXPECT_FAILURE(s2n_find_cipher_pref_from_version("KMS-PQ-TLS-1-0-2019-06", &preferences));
+        EXPECT_EQUAL(preferences, NULL);
+
+        EXPECT_FAILURE(s2n_find_cipher_pref_from_version("PQ-SIKE-TEST-TLS-1-0-2019-11", &preferences));
+        EXPECT_EQUAL(preferences, NULL);
+
+        EXPECT_FAILURE(s2n_find_cipher_pref_from_version("PQ-SIKE-TEST-TLS-1-0-2020-02", &preferences));
+        EXPECT_EQUAL(preferences, NULL);
+
+        EXPECT_FAILURE(s2n_find_cipher_pref_from_version("KMS-PQ-TLS-1-0-2020-02", &preferences));
+        EXPECT_EQUAL(preferences, NULL);
+#endif
 
         preferences = NULL;
         EXPECT_SUCCESS(s2n_find_cipher_pref_from_version("20141001", &preferences));
diff --git a/tests/unit/s2n_hybrid_ecdhe_bike_r1_test.c b/tests/unit/s2n_hybrid_ecdhe_bike_r1_test.c
index 3282b4dcb64..2c8cb6b2c24 100644
--- a/tests/unit/s2n_hybrid_ecdhe_bike_r1_test.c
+++ b/tests/unit/s2n_hybrid_ecdhe_bike_r1_test.c
@@ -27,6 +27,9 @@
 
 int main(int argc, char **argv) {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
@@ -34,5 +37,8 @@ int main(int argc, char **argv) {
 
     EXPECT_SUCCESS(s2n_test_hybrid_ecdhe_kem_with_kat(&s2n_bike1_l1_r1, &s2n_ecdhe_bike_rsa_with_aes_256_gcm_sha384,
             "KMS-PQ-TLS-1-0-2019-06", RSP_FILE_NAME, SERVER_KEY_MESSAGE_LENGTH, CLIENT_KEY_MESSAGE_LENGTH));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_hybrid_ecdhe_bike_r2_test.c b/tests/unit/s2n_hybrid_ecdhe_bike_r2_test.c
index 50c27f299cf..9200cd23653 100644
--- a/tests/unit/s2n_hybrid_ecdhe_bike_r2_test.c
+++ b/tests/unit/s2n_hybrid_ecdhe_bike_r2_test.c
@@ -26,6 +26,9 @@
 
 int main(int argc, char **argv) {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
@@ -33,5 +36,8 @@ int main(int argc, char **argv) {
 
     EXPECT_SUCCESS(s2n_test_hybrid_ecdhe_kem_with_kat(&s2n_bike1_l1_r2, &s2n_ecdhe_bike_rsa_with_aes_256_gcm_sha384,
             "KMS-PQ-TLS-1-0-2020-02", RSP_FILE_NAME, SERVER_KEY_MESSAGE_LENGTH, CLIENT_KEY_MESSAGE_LENGTH));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_hybrid_ecdhe_sike_r1_test.c b/tests/unit/s2n_hybrid_ecdhe_sike_r1_test.c
index 4d65eb69fce..362000e91c6 100644
--- a/tests/unit/s2n_hybrid_ecdhe_sike_r1_test.c
+++ b/tests/unit/s2n_hybrid_ecdhe_sike_r1_test.c
@@ -27,6 +27,9 @@
 
 int main(int argc, char **argv) {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
@@ -34,5 +37,8 @@ int main(int argc, char **argv) {
 
     EXPECT_SUCCESS(s2n_test_hybrid_ecdhe_kem_with_kat(&s2n_sike_p503_r1, &s2n_ecdhe_sike_rsa_with_aes_256_gcm_sha384,
             "KMS-PQ-TLS-1-0-2019-06", RSP_FILE_NAME, SERVER_KEY_MESSAGE_LENGTH, CLIENT_KEY_MESSAGE_LENGTH));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_hybrid_ecdhe_sike_r2_test.c b/tests/unit/s2n_hybrid_ecdhe_sike_r2_test.c
index 9a2fb21e6e7..d8cfa5327eb 100644
--- a/tests/unit/s2n_hybrid_ecdhe_sike_r2_test.c
+++ b/tests/unit/s2n_hybrid_ecdhe_sike_r2_test.c
@@ -26,11 +26,17 @@
 
 int main(int argc, char **argv) {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
     }
     EXPECT_SUCCESS(s2n_test_hybrid_ecdhe_kem_with_kat(&s2n_sike_p434_r2, &s2n_ecdhe_sike_rsa_with_aes_256_gcm_sha384,
             "KMS-PQ-TLS-1-0-2020-02", RSP_FILE_NAME, SERVER_KEY_MESSAGE_LENGTH, CLIENT_KEY_MESSAGE_LENGTH));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_kem_test.c b/tests/unit/s2n_kem_test.c
index 700644aa37b..8afe50798e1 100644
--- a/tests/unit/s2n_kem_test.c
+++ b/tests/unit/s2n_kem_test.c
@@ -94,6 +94,8 @@ int main(int argc, char **argv)
         END_TEST();
     }
 
+#if !defined(S2N_NO_PQ)
+
     {
         /* Regression test for network parsing data of expected sizes */
         EXPECT_EQUAL(sizeof(kem_extension_size), 2);
@@ -300,5 +302,7 @@ int main(int argc, char **argv)
         EXPECT_EQUAL(compatible_params->kems[1]->kem_extension_id, s2n_sike_p434_r2.kem_extension_id);
     }
 
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_kex_with_kem_test.c b/tests/unit/s2n_kex_with_kem_test.c
index 08a3400beac..3c21bb90aa3 100644
--- a/tests/unit/s2n_kex_with_kem_test.c
+++ b/tests/unit/s2n_kex_with_kem_test.c
@@ -152,6 +152,9 @@ static int assert_kex_fips_checks(struct s2n_cipher_suite *cipher_suite, const c
 int main(int argc, char **argv)
 {
     BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode. So we verify functions s2n_check_kem() and
          * s2n_configure_kem() (in s2n_kex.c) are performing their FIPS checks appropriately. */
@@ -198,5 +201,7 @@ int main(int argc, char **argv)
                                   S2N_ERR_KEM_UNSUPPORTED_PARAMS);
     }
 
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_sike_r1_kat_test.c b/tests/unit/s2n_sike_r1_kat_test.c
index 7f8861552d5..92a1c186375 100644
--- a/tests/unit/s2n_sike_r1_kat_test.c
+++ b/tests/unit/s2n_sike_r1_kat_test.c
@@ -27,11 +27,16 @@
 int main(int argc, char **argv, char **envp) {
     BEGIN_TEST();
 
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
     }
 
     EXPECT_SUCCESS(s2n_test_kem_with_kat(&s2n_sike_p503_r1, RSP_FILE));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_sike_r1_kem_test.c b/tests/unit/s2n_sike_r1_kem_test.c
index 28e03cf0821..386087ee06b 100644
--- a/tests/unit/s2n_sike_r1_kem_test.c
+++ b/tests/unit/s2n_sike_r1_kem_test.c
@@ -19,14 +19,16 @@
 
 int main(int argc, char **argv)
 {
+    BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     unsigned char pub_key[SIKE_P503_R1_PUBLIC_KEY_BYTES] = {0};
     unsigned char priv_key[SIKE_P503_R1_SECRET_KEY_BYTES] = {0};
     unsigned char c_shared_secret[SIKE_P503_R1_SHARED_SECRET_BYTES];
     unsigned char s_shared_secret[SIKE_P503_R1_SHARED_SECRET_BYTES];
     unsigned char ciphertext[SIKE_P503_R1_CIPHERTEXT_BYTES];
 
-    BEGIN_TEST();
-
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
@@ -37,5 +39,7 @@ int main(int argc, char **argv)
     EXPECT_SUCCESS(SIKE_P503_r1_crypto_kem_dec(s_shared_secret, ciphertext, priv_key));
     EXPECT_BYTEARRAY_EQUAL(s_shared_secret, c_shared_secret, SIKE_P503_R1_SHARED_SECRET_BYTES);
 
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_sike_r2_kat_test.c b/tests/unit/s2n_sike_r2_kat_test.c
index 730491d8753..6cca8d002ac 100644
--- a/tests/unit/s2n_sike_r2_kat_test.c
+++ b/tests/unit/s2n_sike_r2_kat_test.c
@@ -27,11 +27,16 @@
 int main(int argc, char **argv, char **envp) {
     BEGIN_TEST();
 
+#if !defined(S2N_NO_PQ)
+
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
         END_TEST();
     }
 
     EXPECT_SUCCESS(s2n_test_kem_with_kat(&s2n_sike_p434_r2, RSP_FILE));
+
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_sike_r2_kem_test.c b/tests/unit/s2n_sike_r2_kem_test.c
index d1907253226..deb6fce588f 100644
--- a/tests/unit/s2n_sike_r2_kem_test.c
+++ b/tests/unit/s2n_sike_r2_kem_test.c
@@ -18,18 +18,22 @@
 
 int main(int argc, char **argv)
 {
+    BEGIN_TEST();
+
+#if !defined(S2N_NO_PQ)
+
     unsigned char pub_key[SIKE_P434_R2_PUBLIC_KEY_BYTES] = {0};
     unsigned char priv_key[SIKE_P434_R2_SECRET_KEY_BYTES] = {0};
     unsigned char c_shared_secret[SIKE_P434_R2_SHARED_SECRET_BYTES];
     unsigned char s_shared_secret[SIKE_P434_R2_SHARED_SECRET_BYTES];
     unsigned char ciphertext[SIKE_P434_R2_CIPHERTEXT_BYTES];
 
-    BEGIN_TEST();
-
     EXPECT_SUCCESS(SIKE_P434_r2_crypto_kem_keypair(pub_key, priv_key));
     EXPECT_SUCCESS(SIKE_P434_r2_crypto_kem_enc(ciphertext, c_shared_secret, pub_key));
     EXPECT_SUCCESS(SIKE_P434_r2_crypto_kem_dec(s_shared_secret, ciphertext, priv_key));
     EXPECT_BYTEARRAY_EQUAL(s_shared_secret, c_shared_secret, SIKE_P434_R2_SHARED_SECRET_BYTES);
 
+#endif
+
     END_TEST();
 }
diff --git a/tests/unit/s2n_sike_r2_verify_included_code_test.c b/tests/unit/s2n_sike_r2_verify_included_code_test.c
index 8485125c354..9aebfaccc21 100644
--- a/tests/unit/s2n_sike_r2_verify_included_code_test.c
+++ b/tests/unit/s2n_sike_r2_verify_included_code_test.c
@@ -20,6 +20,7 @@
 int main(int argc, char **argv)
 {
     BEGIN_TEST();
+#if !defined(S2N_NO_PQ)
 
     if (s2n_is_in_fips_mode()) {
         /* There is no support for PQ KEMs while in FIPS mode */
@@ -38,7 +39,9 @@ int main(int argc, char **argv)
     EXPECT_EQUAL(sike_r2_fp_code_identifier(), GENERIC_C_CODE_IDENTIFIER);
 #else
     FAIL_MSG("Neither S2N_PQ_ASM nor S2N_PQ_GENERIC was defined. One of those must be defined.");
-#endif
+#endif /* defined(S2N_PQ_ASM) */
+
+#endif /* !defined(S2N_NO_PQ) */
 
     END_TEST();
 }
diff --git a/tls/s2n_cipher_preferences.c b/tls/s2n_cipher_preferences.c
index 04daac3deb9..61c79549aa8 100644
--- a/tls/s2n_cipher_preferences.c
+++ b/tls/s2n_cipher_preferences.c
@@ -32,6 +32,8 @@
     &s2n_tls13_aes_128_gcm_sha256,          \
     &s2n_tls13_chacha20_poly1305_sha256     \
 
+
+#if !defined(S2N_NO_PQ)
 /* Extension list for round 1 PQ KEMs, in order of preference */
 const struct s2n_kem *pq_kems_r1[2] = {
     &s2n_bike1_l1_r1,
@@ -58,6 +60,8 @@ const struct s2n_kem *pq_kems_sike_r2r1[2] = {
         &s2n_sike_p503_r1,
 };
 
+#endif
+
 /* s2n's list of cipher suites, in order of preferences, as of 2019-08-01 */
 struct s2n_cipher_suite *cipher_suites_20190801[] = {
     S2N_TLS13_CIPHER_SUITES_20190801,
@@ -867,6 +871,8 @@ const struct s2n_cipher_preferences cipher_preferences_kms_tls_1_0_2018_10 = {
     .kems = NULL,
 };
 
+#if !defined(S2N_NO_PQ)
+
 struct s2n_cipher_suite *cipher_suites_kms_pq_tls_1_0_2019_06[] = {
     &s2n_ecdhe_bike_rsa_with_aes_256_gcm_sha384,
     &s2n_ecdhe_sike_rsa_with_aes_256_gcm_sha384,
@@ -934,6 +940,8 @@ const struct s2n_cipher_preferences cipher_preferences_pq_sike_test_tls_1_0_2020
         .kems = pq_kems_sike_r2r1,
 };
 
+#endif
+
 struct s2n_cipher_suite *cipher_suites_kms_fips_tls_1_2_2018_10[] = {
     &s2n_ecdhe_rsa_with_aes_256_gcm_sha384,
     &s2n_ecdhe_rsa_with_aes_128_gcm_sha256,
@@ -980,10 +988,12 @@ struct {
     { .version="CloudFront-TLS-1-2-2018", .preferences=&cipher_preferences_cloudfront_tls_1_2_2018, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="CloudFront-TLS-1-2-2019", .preferences=&cipher_preferences_cloudfront_tls_1_2_2019, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="KMS-TLS-1-0-2018-10", .preferences=&cipher_preferences_kms_tls_1_0_2018_10, .ecc_extension_required=0, .pq_kem_extension_required=0},
+#if !defined(S2N_NO_PQ)
     { .version="KMS-PQ-TLS-1-0-2019-06", .preferences=&cipher_preferences_kms_pq_tls_1_0_2019_06, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="KMS-PQ-TLS-1-0-2020-02", .preferences=&cipher_preferences_kms_pq_tls_1_0_2020_02, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="PQ-SIKE-TEST-TLS-1-0-2019-11", .preferences=&cipher_preferences_pq_sike_test_tls_1_0_2019_11, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="PQ-SIKE-TEST-TLS-1-0-2020-02", .preferences=&cipher_preferences_pq_sike_test_tls_1_0_2020_02, .ecc_extension_required=0, .pq_kem_extension_required=0},
+#endif
     { .version="KMS-FIPS-TLS-1-2-2018-10", .preferences=&cipher_preferences_kms_fips_tls_1_2_2018_10, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="20140601", .preferences=&cipher_preferences_20140601, .ecc_extension_required=0, .pq_kem_extension_required=0},
     { .version="20141001", .preferences=&cipher_preferences_20141001, .ecc_extension_required=0, .pq_kem_extension_required=0},
diff --git a/tls/s2n_cipher_preferences.h b/tls/s2n_cipher_preferences.h
index 5b8973b51dc..ee85b5c798a 100644
--- a/tls/s2n_cipher_preferences.h
+++ b/tls/s2n_cipher_preferences.h
@@ -28,11 +28,15 @@ struct s2n_cipher_preferences {
     const struct s2n_kem **kems;
 };
 
+#if !defined(S2N_NO_PQ)
+
 extern const struct s2n_kem *pq_kems_r1[2];
 extern const struct s2n_kem *pq_kems_r2r1[4];
 extern const struct s2n_kem *pq_kems_sike_r1[1];
 extern const struct s2n_kem *pq_kems_sike_r2r1[2];
 
+#endif
+
 extern const struct s2n_cipher_preferences cipher_preferences_20140601;
 extern const struct s2n_cipher_preferences cipher_preferences_20141001;
 extern const struct s2n_cipher_preferences cipher_preferences_20150202;
diff --git a/tls/s2n_cipher_suites.c b/tls/s2n_cipher_suites.c
index 35b179aaf1d..709485b8e44 100644
--- a/tls/s2n_cipher_suites.c
+++ b/tls/s2n_cipher_suites.c
@@ -775,8 +775,13 @@ const struct s2n_cipher_preferences cipher_preferences_test_all = {
     .count = s2n_array_len(s2n_all_cipher_suites),
     .suites = s2n_all_cipher_suites,
     .minimum_protocol_version = S2N_SSLv3,
+#if !defined(S2N_NO_PQ)
     .kem_count = s2n_array_len(pq_kems_r2r1),
     .kems = pq_kems_r2r1,
+#else
+    .kem_count = 0,
+    .kems = NULL,
+#endif
 };
 
 /* All of the cipher suites that s2n can negotiate when in FIPS mode,
diff --git a/tls/s2n_kem.c b/tls/s2n_kem.c
index fdca75eb2c0..7af537bd6c9 100644
--- a/tls/s2n_kem.c
+++ b/tls/s2n_kem.c
@@ -13,11 +13,6 @@
  * permissions and limitations under the License.
  */
 
-#include "pq-crypto/bike_r1/bike_r1_kem.h"
-#include "pq-crypto/bike_r2/bike_r2_kem.h"
-#include "pq-crypto/sike_r1/sike_r1_kem.h"
-#include "pq-crypto/sike_r2/sike_r2_kem.h"
-
 #include "stuffer/s2n_stuffer.h"
 
 #include "tls/s2n_tls_parameters.h"
@@ -26,6 +21,13 @@
 #include "utils/s2n_mem.h"
 #include "utils/s2n_safety.h"
 
+#if !defined(S2N_NO_PQ)
+
+#include "pq-crypto/bike_r1/bike_r1_kem.h"
+#include "pq-crypto/bike_r2/bike_r2_kem.h"
+#include "pq-crypto/sike_r1/sike_r1_kem.h"
+#include "pq-crypto/sike_r2/sike_r2_kem.h"
+
 /* The names below come from https://tools.ietf.org/html/draft-campagna-tls-bike-sike-hybrid-02#section-5.1.6 */
 const struct s2n_kem s2n_bike1_l1_r1 = {
         .name = "BIKE1r1-Level1",
@@ -100,6 +102,14 @@ const struct s2n_iana_to_kem kem_mapping[2] = {
         }
 };
 
+#else
+
+/* Compiler warns that zero-length arrays are undefined according to the C standard. So make kem_mapping NULL if
+ * Post Quantum ciphers are disabled, and have s2n_cipher_suite_to_kem() detect NULL and treat it as zero-length. */
+const struct s2n_iana_to_kem *kem_mapping = NULL;
+
+#endif
+
 int s2n_kem_generate_keypair(struct s2n_kem_keypair *kem_keys)
 {
     notnull_check(kem_keys);
@@ -236,6 +246,9 @@ int s2n_kem_free(struct s2n_kem_keypair *kem_keys)
 
 int s2n_cipher_suite_to_kem(const uint8_t iana_value[S2N_TLS_CIPHER_SUITE_LEN], const struct s2n_iana_to_kem **compatible_params)
 {
+    /* cppcheck-suppress knownConditionTrueFalse */
+    S2N_ERROR_IF(kem_mapping == NULL, S2N_ERR_KEM_UNSUPPORTED_PARAMS);
+
     for (int i = 0; i < s2n_array_len(kem_mapping); i++) {
         const struct s2n_iana_to_kem *candidate = &kem_mapping[i];
         if (memcmp(iana_value, candidate->iana_value, S2N_TLS_CIPHER_SUITE_LEN) == 0) {
diff --git a/tls/s2n_kem.h b/tls/s2n_kem.h
index ad8afa71e7e..3a9f26a1d7b 100644
--- a/tls/s2n_kem.h
+++ b/tls/s2n_kem.h
@@ -44,11 +44,15 @@ struct s2n_iana_to_kem {
     uint8_t kem_count;
 };
 
+#if !defined(S2N_NO_PQ)
+
 extern const struct s2n_kem s2n_bike1_l1_r1;
 extern const struct s2n_kem s2n_bike1_l1_r2;
 extern const struct s2n_kem s2n_sike_p503_r1;
 extern const struct s2n_kem s2n_sike_p434_r2;
 
+#endif
+
 extern int s2n_kem_generate_keypair(struct s2n_kem_keypair *kem_keys);
 
 extern int s2n_kem_encapsulate(const struct s2n_kem_keypair *kem_keys, struct s2n_blob *shared_secret,
diff --git a/utils/s2n_safety.h b/utils/s2n_safety.h
index 8ddf8537014..228190933e1 100644
--- a/utils/s2n_safety.h
+++ b/utils/s2n_safety.h
@@ -162,7 +162,7 @@ extern int s2n_constant_time_pkcs1_unpad_or_dont(uint8_t * dst, const uint8_t *
   }                                                         \
   struct __useless_struct_to_allow_trailing_semicolon__
 
-#define s2n_array_len(array) (sizeof(array) / sizeof(array[0]))
+#define s2n_array_len(array) ((array != NULL) ? (sizeof(array) / sizeof(array[0])) : 0)
 
 extern int s2n_mul_overflow(uint32_t a, uint32_t b, uint32_t* out);